A scalable route to fabricate nanoscale Zero-Mode Waveguides apertures arrays

Our latest work, published in ACS Photonics, introduces a new strategy to fabricate zero-mode waveguide (ZMW) nanoaperture arrays by sequential multi-step nanoimprint lithography.

ZMWs are powerful nanophotonic structures for single-molecule fluorescence detection, confining excitation light into extremely small volumes and enabling measurements at micromolar concentrations. However, their fabrication typically relies on electron-beam or focused-ion-beam lithography, limiting scalability and throughput.

Here, we exploit the controlled shrinkage of sol-gel materials during annealing to progressively reduce the aperture size over successive imprinting generations. Starting from a single master, four imprinting steps produce ZMWs from 230 nm down to just 115 nm in diameter, without requiring a new high-resolution master at each size.

The resulting structures combine sub-attoliter detection volumes with fluorescence brightness enhancements of up to 20× and more than one million detected photons per second per molecule under saturation. This work demonstrates a scalable route to progressively smaller nanophotonic structures, with strong potential for single-molecule fluorescence and large-area fabrication of nanoscale optical devices.

Beyond ZMW fabrication itself, this work demonstrates how sequential nanoimprint lithography can progressively generate smaller nanophotonic structures from a single master, offering a promising route toward scalable fabrication of nanoscale optical devices. 

Free open-access on ArXiv 2607.09141